# Scramjet Engine:
A scramjet (supersonic combustion ramjet) is a variant of a ramjet air-breathing jet engine in which combustion takes place in supersonic airflow. As in ramjets, a scramjet relies on high vehicle speed to forcefully compress and decelerate the incoming air before combustion (hence ramjet), but whereas a ramjet decelerates the air to subsonic velocities before combustion, airflow in a scramjet is supersonic throughout the entire engine. This allows the scramjet to operate efficiently at extremely high speeds: theoretical projections place the top speed of a scramjet between Mach 12 and Mach 24.
Basic Components:
The scramjet is composed of three basic components.
A converging inlet, where incoming air is compressed and decelerated.
A combustor, where gaseous fuel is burned with atmospheric oxygen to produce heat.
A diverging nozzle, where the heated air is accelerated to produce thrust.
Unlike a typical jet engine, such as a turbojet or turbofan engine, a scramjet does not use rotating, fan-like components to compress the air; rather, the achievable speed of the aircraft moving through the atmosphere causes the air to compress within the inlet. As such, no moving parts are needed in a scramjet. In comparison, typical turbojet engines require inlet fans, multiple stages of rotating compressor fans, and multiple rotating turbine stages, all of which add weight, complexity, and a greater number of failure points to the engine.
Due to the nature of their design, scramjet operation is limited to near-hypersonic velocities. As they lack mechanical compressors, scramjets require the high kinetic energy of a hypersonic flow to compress the incoming air to operational conditions. Thus, a scramjet-powered vehicle must be accelerated to the required velocity by some other means of propulsion, such as turbojet, railgun, or rocket engines.
Advantages
The scramjet is composed of three basic components.
A converging inlet, where incoming air is compressed and decelerated.
A combustor, where gaseous fuel is burned with atmospheric oxygen to produce heat.
A diverging nozzle, where the heated air is accelerated to produce thrust.
Unlike a typical jet engine, such as a turbojet or turbofan engine, a scramjet does not use rotating, fan-like components to compress the air; rather, the achievable speed of the aircraft moving through the atmosphere causes the air to compress within the inlet. As such, no moving parts are needed in a scramjet. In comparison, typical turbojet engines require inlet fans, multiple stages of rotating compressor fans, and multiple rotating turbine stages, all of which add weight, complexity, and a greater number of failure points to the engine.
Due to the nature of their design, scramjet operation is limited to near-hypersonic velocities. As they lack mechanical compressors, scramjets require the high kinetic energy of a hypersonic flow to compress the incoming air to operational conditions. Thus, a scramjet-powered vehicle must be accelerated to the required velocity by some other means of propulsion, such as turbojet, railgun, or rocket engines.
Advantages
- Does not have to carry oxygen.
- No rotating parts makes it easier to manufacture.
- Has a higher specific.
- Higher speed could mean cheaper access to outer space in the future.
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Table of Contents:
- What is scramjet engine?
- Design principles of scramjet engine
- Basic principles of scramjet engine
- Advantages of scramjet engine
- Disadvantages of scramjet engine